1. Field of the Invenntion
The present invention relates to a connector which is used mainly for signal transmission and can prevent generation of crosstalk.
2. Related Art
In recent years, the amount of information to be transmitted has been increasing rapidly in the field of electric communication and, therefore, high-speed signal transmission has been required. To make such high-speed transmission, it is necessary to use a signal of high frequencies. However, use of high-frequency signals increases the amount of a crosstalk between the signals due to the electrostatic coupling thereof. That is, in order to prevent the deteriorated quality of the signals, it is necessary to reduce the crosstalk amount and also, for execution of high-speed signal transmission, it is necessary to prevent the crosstalk not only in signal lines but also in connectors.
Now, a connector, which is generally used for communication, is structured such that two connector elements (a plug and a jack) are connected with each other. The two connector elements respectively include contacts to be connected with the contacts of the partner connector element, terminal piece members with which external electric wires (signal lines) can be connected, and connecting conductors for connecting internally the contacts with the terminal piece members, while these parts are all formed of conductors. In these conductors, there exist portions which are arranged in parallel to each other in a plane. In such parallel portions, since capacity components between the conductors that mutually transmit their partner's signals become unbalanced, a crosstalk current is caused to flow. Also, in the case of the contacts, the allocation of the kinds of signals and position relationship thereof are fixedly regulated by a standard and, therefore, the freedom of design thereof is low. That is, it is difficult to reduce the crosstalk amount in the contacts.
In view of the above, in the connector of this type, there is proposed a structure in which the connecting conductors are disposed in such a manner that, while the plug and jack are coupled to each other, the crosstalk between the terminal piece members of the mutually coupled plug and jack can be reduced. In this case, the connector used as the plug is smaller in dimension than the connector serving as the jack and thus it is difficult to change the arrangement of the connecting conductors of the plug side connector. Therefore, generally, for improvement in the crosstalk characteristic of the connector, the arrangement of the conductors is adjusted in the connector that is used as the jack. Also, as described above, because the contacts are restricted in the arrangement thereof and the terminal piece members are also low in the freedom of arrangement, there have been made trials to reduce the crosstalk by employing the arrangement of the conductors forming the terminal piece members.
For example, as shown in FIG. 9, an electric connector, which is disclosed in Japanese Patent Publication No. 6-84562 of Heisei, is a connector of an 8-pole modular jack type which includes contacts 1, terminal piece members 2 for connection with external electric wires, and connecting conductors 3 respectively interposed between the contacts 1 and terminal piece members 2, while the connecting conductors 3 are in part made to cross each other in two levels. In particular, where numerals (1)-(8) are respectively given to the contacts 1 in this order when viewed from the front surface of the connector (in FIG. 1, from the left side thereof), the connecting conductors 3, which are connected with three pairs of (1)(2) contacts 1, (4)(5) contacts 1 and (7)(8) contacts 1, are respectively made to cross in two levels. A main object of the present structure is to prevent a crosstalk between the pair of (3)(6) contacts 1 and the pair of (4)(5) contacts 1.
When various kinds of signal lines are to be connected by use of a single connector, preferably, the connecting conductors of the connector may be arranged in such a manner that they can prevent generation of the crosstalk between all signal lines. However, in the conventional connector having the above-mentioned structure, since the connecting conductors are all disposed on the same plane, the connecting conductors are also low in the freedom of design and thus it is difficult to design the arrangement of the connecting conductors in such a manner that generation of the crosstalk between all signal lines can be prevented.
On the other hand, in the above-mentioned structure, the connecting conductors 3 arranged substantially in a single plane are in part made to cross each other in a multiple level and, therefore, it is necessary to machine and bend the connecting conductors 3 in order that one of the connecting conductors 3 can cross over the other. Also, since the multi-level crossing portions of the connecting conductors 3 depend on the vertical position relationship between the connecting conductors 3, there arise restrictions on the assembling order of the conductors.